Polymer film composition for rinse release of wash additives

Claim 1

A water-soluble, free-standing polymeric film comprising (a) a first film layer having a thickness of between about 0.5 to 2 mils, and comprising a mixture of hydroxybutylmethylcellulose (HBMC) with a weight average molecular weight of at least about 26,000 g/mole, hydroxypropylmethylcellulose (HPMC) with a weight average molecular weight of at least about 10,000 g/mole, and a first plasticizer, wherein a ratio of HPMC to HBMC is between about 9:1 to 1:1; and (b) a second film layer having a thickness of between about 0.1 to 10 mils, and comprising a mixture of a polyvinyl alcohol having a weight average molecular weight of at least about 10,000 g/mole, a degree of hydrolysis of between about 75% and 95%, a second plasticizer, and a quantity of a cross-linking agent sufficient to reduce the solubility of the film in an alkaline pH, the second film layer and the first film layer being disposed together in an abutting relationship.

Claim 12

A method of making a water-soluble polymeric pouch comprising (a) making a first film layer by combining a hydroxybutylmethylcellulose (HBMC) resin, having a molecular weight of at least about 26,000 g/mole, a hydroxypropylmethylcellulose (HPMC) resin having a molecular weight of at least about 10,000 g/mole, wherein a ratio of HPMC to HBMC is between about 9 to 1 and 1 to 1, adding thereto a plasticizer in an amount sufficient to plasticize said resin blend, and forming the resulting mixture into a film approximately 0.5 to 2 mils thick; (b) making a second film layer by combining about 60% to 90% of a polyvinyl alcohol resin having a molecular weight of at least about 10,000 g/mole and a degree of hydrolysis of between about 75% to 95%, with a plasticizer in an amount sufficient to plasticize the PVA resin, and a quantity of a cross-linking agent sufficient to reduce the solubility of the film in an alkaline pH, and forming the resulting mixture into a film of about 0.1 to 10 mils thick; and (c) forming a sealable pouch of the first and second film layers wherein the first film layer is disposed toward an exterior of the pouch and the second film layer is disposed toward an interior of the pouch, and whereby an additive may be sealed therein.

Claim 13

A method of making a water-soluble polymeric pouch comprising (a) making a first film layer by combining a hydroxybutylmethylcellulose (HBMC) resin, having a molecular weight of at least about 26,000 g/mole, a hydroxypropylmethylcellulose (HPMC) resin having a molecular weight of at least about 10,000 g/mole, wherein a ratio of HPMC to HBMC is between about 9 to 1 and 1 to 1, adding thereto a plasticizer in an amount sufficient to plasticize said resin blend, and forming the resulting mixture into a film approximately 0.5 to 2 mils thick; (b) making a second film layer by combining about 60% to 90% of a polyvinyl alcohol resin having a molecular weight of at least about 10,000 g/mole and a degree of hydrolysis of between about 75% to 95%, with a plasticizer in an amount sufficient to plasticize the PVA resin, and a quantity of a cross-linking agent sufficient to reduce the solubility of the film in an alkaline pH, and forming the resulting mixture into a film of about 0.1 to 10 mils thick; and (c) forming a sealable pouch of the first and second film layers wherein the first film layer is disposed toward an exterior of the pouch and the second film layer is disposed toward an interior of the pouch, and whereby an additive may be sealed therein.

Claim 14

A method for introducing a wash additive to an aqueous laundry solution during a rinse portion of a wash cycle, comprising (a) enclosing an additive in a container having at least one water-soluble polymeric film portion comprising a first, outer film layer having a thickness of between about 0.5 and 2 mils, and comprising a blend of an hydroxybutylmethylcellulose (HBMC) resin, having a weight average molecular weight of at least about 26,000 g/mole, and HPMC resin having a weight average molecular weight of at least about 10,000 g/mole, the HPMC resin being present in an amount of between about one to nine times the amount of hydroxybutylmethylcellulose (HBMC), and a plasticizer in an amount sufficient to plasticize the blend into a film, a second, inner film layer, having a thickness of between about 0.1 and 10 mils, and comprising a polyvinyl alcohol resin having a weight average molecular weight of at least about 10,000 and a degree of hydrolysis of between about 75% and 95%, a second plasticizer in an amount sufficient to plasticize said resin into a film, wherein the additive is disposed adjacent to and within the second film layer, which is adjacent to and disposed within the first film layer; (b) adding the container to a first aqueous laundry solution, having a first pH; (c) maintaining at least said water-soluble film portion of the container in said first solution in the presence of a cross-linking agent, present in an amount sufficient to reduce the solubility of the PVA in said first solution; and (d) replacing said first aqueous solution with a second aqueous solution having a second pH, said second pH being less than said first pH whereby said water-soluble film portion solubilizes, freeing the additive contained therein.

Claim 15

A method for introducing a wash additive to an aqueous laundry solution during a rinse portion of a wash cycle, comprising (a) enclosing an additive in a container having at least one water-soluble polymeric film portion comprising a first, outer film layer having a thickness of between about 0.5 and 2 mils, and comprising a blend of an hydroxybutylmethylcellulose (HBMC) resin, having a weight average molecular weight of at least about 26,000 g/mole, and HPMC resin having a weight average molecular weight of at least about 10,000 g/mole, the HPMC resin being present in an amount of between about one to nine times the amount of hydroxybutylmethylcellulose (HBMC), and a plasticizer in an amount sufficient to plasticize the blend into a film, a second, inner film layer, having a thickness of between about 0.1 and 10 mils, and comprising a polyvinyl alcohol resin having a weight average molecular weight of at least about 10,000 and a degree of hydrolysis of between about 75% and 95%, a second plasticizer in an amount sufficient to plasticize said resin into a film, wherein the additive is disposed adjacent to and within the second film layer, which is adjacent to and disposed within the first film layer; (b) adding the container to a first aqueous laundry solution, having a first pH; (c) maintaining at least said water-soluble film portion of the container in said first solution in the presence of a cross-linking agent, present in an amount sufficient to reduce the solubility of the PVA in said first solution; and (d) replacing said first aqueous solution with a second aqueous solution having a second pH, said second pH being less than said first pH whereby said water-soluble film portion solubilizes, freeing the additive contained therein.